Rework the CustomExpression evaluation to use SimulationListeners. Removed the OpenRocketDocument member variable from the Simulation object.

android/src/net/sf/openrocket/android/CurrentRocket.java

@@ -75,8 +75,7 @@ public class CurrentRocket {
 	public synchronized void addNewSimulation( Context context ) {
 		isModified = true;
 		Rocket rocket = rocketDocument.getRocket();
-		// FIXME - hopefully the change to the Simulation object will be reverted soon.
+		Simulation newSim = new Simulation(rocket);
-		Simulation newSim = new Simulation(rocketDocument, rocket);
 		newSim.setName(rocketDocument.getNextSimulationName());
 		rocketDocument.addSimulation(newSim);
 		notifySimsChanged(context);

core/src/net/sf/openrocket/document/OpenRocketDocument.java

@@ -117,7 +117,7 @@ public class OpenRocketDocument implements ComponentChangeListener {
 		customExpressions.remove(expression);
 	}
 	
-	public ArrayList<CustomExpression> getCustomExpressions(){
+	public List<CustomExpression> getCustomExpressions(){
 		return customExpressions;
 	}
 	

core/src/net/sf/openrocket/document/Simulation.java

@@ -60,7 +60,6 @@ public class Simulation implements ChangeSource, Cloneable {
 	private SafetyMutex mutex = SafetyMutex.newInstance();
 	
 	private final Rocket rocket;
-	private final OpenRocketDocument document;
 	
 	private String name = "";
 	
@@ -94,11 +93,7 @@ public class Simulation implements ChangeSource, Cloneable {
 	 * 
 	 * @param rocket	the rocket associated with the simulation.
 	 */
-	public Simulation(OpenRocketDocument doc, Rocket rocket) {
+	public Simulation(Rocket rocket) {
-		// It may seem silly to pass in the document and rocket, since usually when called we 
-		// use doc.getRocket, but I guess there is some reason; when cloning a simulation + rocket we don't need
-		// to make a duplicate of the undo data etc stored in the document. --Richard
-		this.document = doc;
 		this.rocket = rocket;
 		this.status = Status.NOT_SIMULATED;
 		
@@ -109,7 +104,7 @@ public class Simulation implements ChangeSource, Cloneable {
 	}
 	
 	
-	public Simulation(OpenRocketDocument doc, Rocket rocket, Status status, String name, SimulationOptions options,
+	public Simulation(Rocket rocket, Status status, String name, SimulationOptions options,
 			List<String> listeners, FlightData data) {
 		
 		if (rocket == null)
@@ -122,7 +117,6 @@ public class Simulation implements ChangeSource, Cloneable {
 			throw new IllegalArgumentException("options cannot be null");
 		
 		this.rocket = rocket;
-		this.document = doc;
 		
 		if (status == Status.UPTODATE) {
 			this.status = Status.LOADED;
@@ -152,13 +146,6 @@ public class Simulation implements ChangeSource, Cloneable {
 		
 	}
 	
-	/*
-	 * Return the parent document for this simulation
-	 */
-	public OpenRocketDocument getDocument(){
-		return document;
-	}
-	
 	/**
 	 * Return the rocket associated with this simulation.
 	 * 
@@ -423,7 +410,7 @@ public class Simulation implements ChangeSource, Cloneable {
 	public Simulation duplicateSimulation(Rocket newRocket) {
 		mutex.lock("duplicateSimulation");
 		try {
-			Simulation copy = new Simulation(document, newRocket);
+			Simulation copy = new Simulation(newRocket);
 			
 			copy.name = this.name;
 			copy.options.copyFrom(this.options);

core/src/net/sf/openrocket/file/openrocket/importt/OpenRocketLoader.java

@@ -1383,7 +1383,7 @@ class SingleSimulationHandler extends AbstractElementHandler {
 		else
 			data = dataHandler.getFlightData();
 
-		Simulation simulation = new Simulation(doc, doc.getRocket(), status, name,
+		Simulation simulation = new Simulation(doc.getRocket(), status, name,
 				conditions, listeners, data);
 				
 		doc.addSimulation(simulation);

core/src/net/sf/openrocket/gui/customexpression/CustomExpressionPanel.java

@@ -5,8 +5,8 @@ import java.awt.Window;
 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
 import java.io.File;
-import java.util.ArrayList;
 import java.util.Collections;
+import java.util.List;
 
 import javax.swing.BorderFactory;
 import javax.swing.JButton;
@@ -17,23 +17,17 @@ import javax.swing.JPanel;
 import javax.swing.JScrollPane;
 import javax.swing.SwingUtilities;
 import javax.swing.border.Border;
-import javax.swing.filechooser.FileFilter;
 import javax.swing.filechooser.FileNameExtensionFilter;
 
 import net.miginfocom.swing.MigLayout;
 import net.sf.openrocket.document.OpenRocketDocument;
 import net.sf.openrocket.file.DatabaseMotorFinder;
 import net.sf.openrocket.file.GeneralRocketLoader;
-import net.sf.openrocket.file.MotorFinder;
 import net.sf.openrocket.file.RocketLoadException;
-import net.sf.openrocket.document.Simulation;
-import net.sf.openrocket.gui.components.DescriptionArea;
 import net.sf.openrocket.gui.components.UnitSelector;
-import net.sf.openrocket.gui.customexpression.ExpressionBuilderDialog;
 import net.sf.openrocket.gui.util.Icons;
 import net.sf.openrocket.l10n.Translator;
 import net.sf.openrocket.logging.LogHelper;
-import net.sf.openrocket.rocketcomponent.Rocket;
 import net.sf.openrocket.simulation.customexpression.CustomExpression;
 import net.sf.openrocket.startup.Application;
 
@@ -158,7 +152,7 @@ public class CustomExpressionPanel extends JPanel {
 	 * @param move integer - +1 to move down, -1 to move up
 	 */
 	private void moveExpression(CustomExpression expression, int move){
-		ArrayList<CustomExpression> expressions = doc.getCustomExpressions();
+		List<CustomExpression> expressions = doc.getCustomExpressions();
 		int i = expressions.indexOf(expression);
 		if (i+move == expressions.size() || i+move < 0)
 			return;

core/src/net/sf/openrocket/gui/dialogs/optimization/GeneralOptimizationDialog.java

@@ -1000,14 +1000,14 @@ public class GeneralOptimizationDialog extends JDialog {
 			if (id == null) {
 				continue;
 			}
-			Simulation sim = new Simulation(documentCopy, rocket);
+			Simulation sim = new Simulation(rocket);
 			sim.getConfiguration().setMotorConfigurationID(id);
 			String name = createSimulationName(trans.get("basicSimulationName"), rocket.getMotorConfigurationNameOrDescription(id));
 			simulations.add(new Named<Simulation>(sim, name));
 		}
 		
 		
-		Simulation sim = new Simulation(documentCopy, rocket);
+		Simulation sim = new Simulation(rocket);
 		sim.getConfiguration().setMotorConfigurationID(null);
 		String name = createSimulationName(trans.get("noSimulationName"), rocket.getMotorConfigurationNameOrDescription(null));
 		simulations.add(new Named<Simulation>(sim, name));

core/src/net/sf/openrocket/gui/main/SimulationEditDialog.java

@@ -30,6 +30,7 @@ import javax.swing.event.DocumentEvent;
 import javax.swing.event.DocumentListener;
 
 import net.miginfocom.swing.MigLayout;
+import net.sf.openrocket.document.OpenRocketDocument;
 import net.sf.openrocket.document.Simulation;
 import net.sf.openrocket.gui.SpinnerEditor;
 import net.sf.openrocket.gui.adaptors.BooleanModel;
@@ -41,7 +42,6 @@ import net.sf.openrocket.gui.components.DescriptionArea;
 import net.sf.openrocket.gui.components.SimulationExportPanel;
 import net.sf.openrocket.gui.components.UnitSelector;
 import net.sf.openrocket.gui.plot.Axis;
-import net.sf.openrocket.gui.customexpression.CustomExpressionPanel;
 import net.sf.openrocket.gui.plot.PlotConfiguration;
 import net.sf.openrocket.gui.plot.SimulationPlotPanel;
 import net.sf.openrocket.gui.util.GUIUtil;
@@ -83,19 +83,20 @@ public class SimulationEditDialog extends JDialog {
 
 	private final Window parentWindow;
 	private final Simulation simulation;
+	private final OpenRocketDocument document;
 	private final SimulationOptions conditions;
 	private final Configuration configuration;
 	private static final Translator trans = Application.getTranslator();
 	
 	
-	public SimulationEditDialog(Window parent, Simulation s) {
+	public SimulationEditDialog(Window parent, OpenRocketDocument document, Simulation s) {
-		this(parent, s, 0);
+		this(parent, document, s, 0);
 	}
 	
-	public SimulationEditDialog(Window parent, Simulation s, int tab) {
+	public SimulationEditDialog(Window parent, OpenRocketDocument document, Simulation s, int tab) {
 		//// Edit simulation
 		super(parent, trans.get("simedtdlg.title.Editsim"), JDialog.ModalityType.DOCUMENT_MODAL);
-		
+		this.document = document;
 		this.parentWindow = parent;
 		this.simulation = s;
 		this.conditions = simulation.getOptions();
@@ -170,7 +171,7 @@ public class SimulationEditDialog extends JDialog {
 			@Override
 			public void actionPerformed(ActionEvent e) {
 				SimulationEditDialog.this.dispose();
-				SimulationRunDialog.runSimulations(parentWindow, simulation);
+				SimulationRunDialog.runSimulations(parentWindow, SimulationEditDialog.this.document, simulation);
 			}
 		});
 		mainPanel.add(button, "gapright para");

core/src/net/sf/openrocket/gui/main/SimulationPanel.java

@@ -82,7 +82,7 @@ public class SimulationPanel extends JPanel {
 		button.addActionListener(new ActionListener() {
 			@Override
 			public void actionPerformed(ActionEvent e) {
-				Simulation sim = new Simulation(document, document.getRocket());
+				Simulation sim = new Simulation(document.getRocket());
 				sim.setName(document.getNextSimulationName());
 				
 				int n = document.getSimulationCount();
@@ -135,7 +135,7 @@ public class SimulationPanel extends JPanel {
 				
 				long t = System.currentTimeMillis();
 				new SimulationRunDialog(SwingUtilities.getWindowAncestor(
-							SimulationPanel.this), sims).setVisible(true);
+							SimulationPanel.this), document, sims).setVisible(true);
 				log.info("Running simulations took " + (System.currentTimeMillis() - t) + " ms");
 				fireMaintainSelection();
 			}
@@ -514,7 +514,7 @@ public class SimulationPanel extends JPanel {
 	}
 	
 	private void openDialog(final Simulation sim, int position) {
-		new SimulationEditDialog(SwingUtilities.getWindowAncestor(this), sim, position)
+		new SimulationEditDialog(SwingUtilities.getWindowAncestor(this), document, sim, position)
 				.setVisible(true);
 		fireMaintainSelection();
 	}

core/src/net/sf/openrocket/gui/main/SimulationRunDialog.java

@@ -24,6 +24,7 @@ import javax.swing.JPanel;
 import javax.swing.JProgressBar;
 
 import net.miginfocom.swing.MigLayout;
+import net.sf.openrocket.document.OpenRocketDocument;
 import net.sf.openrocket.document.Simulation;
 import net.sf.openrocket.gui.dialogs.DetailDialog;
 import net.sf.openrocket.gui.util.GUIUtil;
@@ -35,6 +36,8 @@ import net.sf.openrocket.rocketcomponent.MotorMount;
 import net.sf.openrocket.rocketcomponent.MotorMount.IgnitionEvent;
 import net.sf.openrocket.simulation.FlightEvent;
 import net.sf.openrocket.simulation.SimulationStatus;
+import net.sf.openrocket.simulation.customexpression.CustomExpression;
+import net.sf.openrocket.simulation.customexpression.CustomExpressionSimulationListener;
 import net.sf.openrocket.simulation.exception.SimulationCancelledException;
 import net.sf.openrocket.simulation.exception.SimulationException;
 import net.sf.openrocket.simulation.exception.SimulationLaunchException;
@@ -95,6 +98,7 @@ public class SimulationRunDialog extends JDialog {
 	 * will result in an exception being thrown!
 	 */
 	private final Simulation[] simulations;
+	private final OpenRocketDocument document;
 	private final String[] simulationNames;
 	private final SimulationWorker[] simulationWorkers;
 	private final SimulationStatus[] simulationStatuses;
@@ -102,9 +106,10 @@ public class SimulationRunDialog extends JDialog {
 	private final double[] simulationMaxVelocity;
 	private final boolean[] simulationDone;
 	
-	public SimulationRunDialog(Window window, Simulation... simulations) {
+	public SimulationRunDialog(Window window, OpenRocketDocument document, Simulation... simulations) {
 		//// Running simulations...
 		super(window, trans.get("SimuRunDlg.title.RunSim"), Dialog.ModalityType.APPLICATION_MODAL);
+		this.document = document;
 		
 		if (simulations.length == 0) {
 			throw new IllegalArgumentException("Called with no simulations to run");
@@ -129,7 +134,7 @@ public class SimulationRunDialog extends JDialog {
 		
 		for (int i = 0; i < n; i++) {
 			simulationNames[i] = simulations[i].getName();
-			simulationWorkers[i] = new InteractiveSimulationWorker(simulations[i], i);
+			simulationWorkers[i] = new InteractiveSimulationWorker(document, simulations[i], i);
 			executor.execute(simulationWorkers[i]);
 		}
 		
@@ -208,8 +213,8 @@ public class SimulationRunDialog extends JDialog {
 	 * @param parent		the parent Window of the dialog to use.
 	 * @param simulations	the simulations to run.
 	 */
-	public static void runSimulations(Window parent, Simulation... simulations) {
+	public static void runSimulations(Window parent, OpenRocketDocument document, Simulation... simulations) {
-		new SimulationRunDialog(parent, simulations).setVisible(true);
+		new SimulationRunDialog(parent, document, simulations).setVisible(true);
 	}
 	
 	
@@ -277,6 +282,8 @@ public class SimulationRunDialog extends JDialog {
 		private volatile double burnoutVelocity;
 		private volatile double apogeeAltitude;
 		
+		private final CustomExpressionSimulationListener exprListener;
+		
 		/*
 		 * -2 = time from 0 ... burnoutTimeEstimate
 		 * -1 = velocity from v(burnoutTimeEstimate) ... 0
@@ -287,8 +294,10 @@ public class SimulationRunDialog extends JDialog {
 		private int progress = 0;
 		
 		
-		public InteractiveSimulationWorker(Simulation sim, int index) {
+		public InteractiveSimulationWorker(OpenRocketDocument doc, Simulation sim, int index) {
 			super(sim);
+			List<CustomExpression> exprs = doc.getCustomExpressions();
+			exprListener = new CustomExpressionSimulationListener(exprs);
 			this.index = index;
 			
 			// Calculate estimate of motor burn time
@@ -314,7 +323,7 @@ public class SimulationRunDialog extends JDialog {
 		 */
 		@Override
 		protected SimulationListener[] getExtraListeners() {
-			return new SimulationListener[] { new SimulationProgressListener() };
+			return new SimulationListener[] { new SimulationProgressListener(), exprListener };
 		}
 		
 		

core/src/net/sf/openrocket/gui/scalefigure/RocketPanel.java

@@ -62,6 +62,8 @@ import net.sf.openrocket.rocketcomponent.Rocket;
 import net.sf.openrocket.rocketcomponent.RocketComponent;
 import net.sf.openrocket.rocketcomponent.SymmetricComponent;
 import net.sf.openrocket.simulation.FlightData;
+import net.sf.openrocket.simulation.customexpression.CustomExpression;
+import net.sf.openrocket.simulation.customexpression.CustomExpressionSimulationListener;
 import net.sf.openrocket.simulation.listeners.SimulationListener;
 import net.sf.openrocket.simulation.listeners.system.ApogeeEndListener;
 import net.sf.openrocket.simulation.listeners.system.InterruptListener;
@@ -87,47 +89,47 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 	private boolean is3d;
 	private final RocketFigure figure;
 	private final RocketFigure3d figure3d;
-	
+
-	
+
 	private final ScaleScrollPane scrollPane;
-	
+
 	private final JPanel figureHolder;
-	
+
 	private JLabel infoMessage;
-	
+
 	private TreeSelectionModel selectionModel = null;
-	
+
 	private BasicSlider rotationSlider;
 	ScaleSelector scaleSelector;
-	
+
 
 	/* Calculation of CP and CG */
 	private AerodynamicCalculator aerodynamicCalculator;
 	private MassCalculator massCalculator;
-	
+
 
 	private final OpenRocketDocument document;
 	private final Configuration configuration;
-	
+
 	private Caret extraCP = null;
 	private Caret extraCG = null;
 	private RocketInfo extraText = null;
-	
+
 
 	private double cpAOA = Double.NaN;
 	private double cpTheta = Double.NaN;
 	private double cpMach = Double.NaN;
 	private double cpRoll = Double.NaN;
-	
+
 	// The functional ID of the rocket that was simulated
 	private int flightDataFunctionalID = -1;
 	private String flightDataMotorID = null;
-	
+
 
 	private SimulationWorker backgroundSimulationWorker = null;
-	
+
 	private List<EventListener> listeners = new ArrayList<EventListener>();
-	
+
 
 	/**
 	 * The executor service used for running the background simulations.
@@ -138,34 +140,34 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 	static {
 		backgroundSimulationExecutor = Executors.newFixedThreadPool(SwingPreferences.getMaxThreadCount(),
 				new ThreadFactory() {
-					private ThreadFactory factory = Executors.defaultThreadFactory();
+			private ThreadFactory factory = Executors.defaultThreadFactory();
-					
+
-					@Override
+			@Override
-					public Thread newThread(Runnable r) {
+			public Thread newThread(Runnable r) {
-						Thread t = factory.newThread(r);
+				Thread t = factory.newThread(r);
-						t.setDaemon(true);
+				t.setDaemon(true);
-						t.setPriority(Thread.MIN_PRIORITY);
+				t.setPriority(Thread.MIN_PRIORITY);
-						return t;
+				return t;
-					}
+			}
-				});
+		});
 	}
-	
+
-	
+
 	public RocketPanel(OpenRocketDocument document) {
-		
+
 		this.document = document;
 		configuration = document.getDefaultConfiguration();
-		
+
 		// TODO: FUTURE: calculator selection
 		aerodynamicCalculator = new BarrowmanCalculator();
 		massCalculator = new BasicMassCalculator();
-		
+
 		// Create figure and custom scroll pane
 		figure = new RocketFigure(configuration);
 		figure3d = new RocketFigure3d(configuration);
-		
+
 		figureHolder = new JPanel(new BorderLayout());
-		
+
 		scrollPane = new ScaleScrollPane(figure) {
 			private static final long serialVersionUID = 1L;
 
@@ -176,12 +178,12 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 		};
 		scrollPane.getViewport().setScrollMode(JViewport.SIMPLE_SCROLL_MODE);
 		scrollPane.setFitting(true);
-		
+
 		createPanel();
-		
+
 		is3d = true;
 		go2D();
-		
+
 		configuration.addChangeListener(new StateChangeListener() {
 			@Override
 			public void stateChanged(EventObject e) {
@@ -190,7 +192,7 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 				updateFigures();
 			}
 		});
-		
+
 		figure3d.addComponentSelectionListener(new RocketFigure3d.ComponentSelectionListener() {
 			@Override
 			public void componentClicked(RocketComponent clicked[], MouseEvent event) {
@@ -198,7 +200,7 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 			}
 		});
 	}
-	
+
 	private void updateFigures() {
 		if (!is3d)
 			figure.updateFigure();
@@ -233,20 +235,20 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 		figureHolder.revalidate();
 		figure.repaint();
 	}
-	
+
 	/**
 	 * Creates the layout and components of the panel.
 	 */
 	private void createPanel() {
 		setLayout(new MigLayout("", "[shrink][grow]", "[shrink][shrink][grow][shrink]"));
-		
+
 		setPreferredSize(new Dimension(800, 300));
-		
+
 
 		//// Create toolbar
-		
+
 		ButtonGroup bg = new ButtonGroup();
-		
+
 		// Side/back buttons
 		FigureTypeAction action = new FigureTypeAction(RocketFigure.TYPE_SIDE);
 		//// Side view
@@ -256,7 +258,7 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 		JToggleButton toggle = new JToggleButton(action);
 		bg.add(toggle);
 		add(toggle, "spanx, split");
-		
+
 		action = new FigureTypeAction(RocketFigure.TYPE_BACK);
 		//// Back view
 		action.putValue(Action.NAME, trans.get("RocketPanel.FigTypeAct.Backview"));
@@ -265,7 +267,7 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 		toggle = new JToggleButton(action);
 		bg.add(toggle);
 		add(toggle, "gap rel");
-		
+
 		//// 3d Toggle
 		final JToggleButton toggle3d = new JToggleButton(new AbstractAction("3D") {
 			private static final long serialVersionUID = 1L;
@@ -284,18 +286,18 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 		});
 		bg.add(toggle3d);
 		add(toggle3d, "gap rel");
-		
+
 
 		// Zoom level selector
 		scaleSelector = new ScaleSelector(scrollPane);
 		add(scaleSelector);
-		
+
 
 
 		// Stage selector
 		StageSelector stageSelector = new StageSelector(configuration);
 		add(stageSelector, "");
-		
+
 
 
 		// Motor configuration selector
@@ -304,55 +306,55 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 		label.setHorizontalAlignment(JLabel.RIGHT);
 		add(label, "growx, right");
 		add(new JComboBox(new MotorConfigurationModel(configuration)), "wrap");
-		
+
 
 
 
 
 		// Create slider and scroll pane
-		
+
 		DoubleModel theta = new DoubleModel(figure, "Rotation",
 				UnitGroup.UNITS_ANGLE, 0, 2 * Math.PI);
 		UnitSelector us = new UnitSelector(theta, true);
 		us.setHorizontalAlignment(JLabel.CENTER);
 		add(us, "alignx 50%, growx");
-		
+
 		// Add the rocket figure
 		add(figureHolder, "grow, spany 2, wmin 300lp, hmin 100lp, wrap");
-		
+
 
 		// Add rotation slider
 		// Minimum size to fit "360deg"
 		JLabel l = new JLabel("360" + Chars.DEGREE);
 		Dimension d = l.getPreferredSize();
-		
+
 		add(rotationSlider = new BasicSlider(theta.getSliderModel(0, 2 * Math.PI), JSlider.VERTICAL, true),
 				"ax 50%, wrap, width " + (d.width + 6) + "px:null:null, growy");
-		
+
 
 		//// <html>Click to select &nbsp;&nbsp; Shift+click to select other &nbsp;&nbsp; Double-click to edit &nbsp;&nbsp; Click+drag to move
 		infoMessage = new JLabel(trans.get("RocketPanel.lbl.infoMessage"));
 		infoMessage.setFont(new Font("Sans Serif", Font.PLAIN, 9));
 		add(infoMessage, "skip, span, gapleft 25, wrap");
-		
+
 
 		addExtras();
 	}
-	
+
-	
+
 
 	public RocketFigure getFigure() {
 		return figure;
 	}
-	
+
 	public AerodynamicCalculator getAerodynamicCalculator() {
 		return aerodynamicCalculator;
 	}
-	
+
 	public Configuration getConfiguration() {
 		return configuration;
 	}
-	
+
 	/**
 	 * Get the center of pressure figure element.
 	 * 
@@ -361,7 +363,7 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 	public Caret getExtraCP() {
 		return extraCP;
 	}
-	
+
 	/**
 	 * Get the center of gravity figure element.
 	 * 
@@ -370,7 +372,7 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 	public Caret getExtraCG() {
 		return extraCG;
 	}
-	
+
 	/**
 	 * Get the extra text figure element.
 	 * 
@@ -379,7 +381,7 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 	public RocketInfo getExtraText() {
 		return extraText;
 	}
-	
+
 	public void setSelectionModel(TreeSelectionModel m) {
 		if (selectionModel != null) {
 			selectionModel.removeTreeSelectionListener(this);
@@ -388,8 +390,8 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 		selectionModel.addTreeSelectionListener(this);
 		valueChanged((TreeSelectionEvent) null); // updates FigureParameters
 	}
-	
+
-	
+
 
 	/**
 	 * Return the angle of attack used in CP calculation.  NaN signifies the default value
@@ -399,7 +401,7 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 	public double getCPAOA() {
 		return cpAOA;
 	}
-	
+
 	/**
 	 * Set the angle of attack to be used in CP calculation.  A value of NaN signifies that
 	 * the default AOA (zero) should be used.
@@ -414,11 +416,11 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 		updateFigures();
 		fireChangeEvent();
 	}
-	
+
 	public double getCPTheta() {
 		return cpTheta;
 	}
-	
+
 	public void setCPTheta(double theta) {
 		if (MathUtil.equals(theta, cpTheta) ||
 				(Double.isNaN(theta) && Double.isNaN(cpTheta)))
@@ -430,11 +432,11 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 		updateFigures();
 		fireChangeEvent();
 	}
-	
+
 	public double getCPMach() {
 		return cpMach;
 	}
-	
+
 	public void setCPMach(double mach) {
 		if (MathUtil.equals(mach, cpMach) ||
 				(Double.isNaN(mach) && Double.isNaN(cpMach)))
@@ -444,11 +446,11 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 		updateFigures();
 		fireChangeEvent();
 	}
-	
+
 	public double getCPRoll() {
 		return cpRoll;
 	}
-	
+
 	public void setCPRoll(double roll) {
 		if (MathUtil.equals(roll, cpRoll) ||
 				(Double.isNaN(roll) && Double.isNaN(cpRoll)))
@@ -458,19 +460,19 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 		updateFigures();
 		fireChangeEvent();
 	}
-	
+
-	
+
 
 	@Override
 	public void addChangeListener(EventListener listener) {
 		listeners.add(0, listener);
 	}
-	
+
 	@Override
 	public void removeChangeListener(EventListener listener) {
 		listeners.remove(listener);
 	}
-	
+
 	protected void fireChangeEvent() {
 		EventObject e = new EventObject(this);
 		for (EventListener l : listeners) {
@@ -479,8 +481,8 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 			}
 		}
 	}
-	
+
-	
+
 
 
 	/**
@@ -493,7 +495,7 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 	 * the next component. Otherwise select the first component in the list. 
 	 */
 	public static final int CYCLE_SELECTION_MODIFIER = InputEvent.SHIFT_DOWN_MASK;
-	
+
 	private void handleMouseClick(MouseEvent event) {
 		if (event.getButton() != MouseEvent.BUTTON1)
 			return;
@@ -501,18 +503,18 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 		Point p1 = scrollPane.getViewport().getViewPosition();
 		int x = p0.x + p1.x;
 		int y = p0.y + p1.y;
-		
+
 		RocketComponent[] clicked = figure.getComponentsByPoint(x, y);
-		
+
 		handleComponentClick(clicked, event);
 	}
-	
+
 	private void handleComponentClick(RocketComponent[] clicked, MouseEvent event){
-		
+
 		// If no component is clicked, do nothing
 		if (clicked.length == 0)
 			return;
-		
+
 		// Check whether the currently selected component is in the clicked components.
 		TreePath path = selectionModel.getSelectionPath();
 		if (path != null) {
@@ -529,7 +531,7 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 				}
 			}
 		}
-		
+
 		// Currently selected component not clicked
 		if (path == null) {
 			if (event.isShiftDown() && event.getClickCount() == 1 && clicked.length > 1) {
@@ -538,18 +540,18 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 				path = ComponentTreeModel.makeTreePath(clicked[0]);
 			}
 		}
-		
+
 		// Set selection and check for double-click
 		selectionModel.setSelectionPath(path);
 		if (event.getClickCount() == 2) {
 			RocketComponent component = (RocketComponent) path.getLastPathComponent();
-			
+
 			ComponentConfigDialog.showDialog(SwingUtilities.getWindowAncestor(this),
 					document, component);
 		}
 	}
-	
+
-	
+
 
 
 	/**
@@ -557,15 +559,15 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 	 * the CP and CG carets.
 	 */
 	private WarningSet warnings = new WarningSet();
-	
+
 	private void updateExtras() {
 		Coordinate cp, cg;
 		double cpx, cgx;
-		
+
 		// TODO: MEDIUM: User-definable conditions
 		FlightConditions conditions = new FlightConditions(configuration);
 		warnings.clear();
-		
+
 		if (!Double.isNaN(cpMach)) {
 			conditions.setMach(cpMach);
 			extraText.setMach(cpMach);
@@ -573,20 +575,20 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 			conditions.setMach(Application.getPreferences().getDefaultMach());
 			extraText.setMach(Application.getPreferences().getDefaultMach());
 		}
-		
+
 		if (!Double.isNaN(cpAOA)) {
 			conditions.setAOA(cpAOA);
 		} else {
 			conditions.setAOA(0);
 		}
 		extraText.setAOA(cpAOA);
-		
+
 		if (!Double.isNaN(cpRoll)) {
 			conditions.setRollRate(cpRoll);
 		} else {
 			conditions.setRollRate(0);
 		}
-		
+
 		if (!Double.isNaN(cpTheta)) {
 			conditions.setTheta(cpTheta);
 			cp = aerodynamicCalculator.getCP(configuration, conditions, warnings);
@@ -594,24 +596,24 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 			cp = aerodynamicCalculator.getWorstCP(configuration, conditions, warnings);
 		}
 		extraText.setTheta(cpTheta);
-		
+
 
 		cg = massCalculator.getCG(configuration, MassCalcType.LAUNCH_MASS);
 		//		System.out.println("CG computed as "+cg+ " CP as "+cp);
-		
+
 		if (cp.weight > 0.000001)
 			cpx = cp.x;
 		else
 			cpx = Double.NaN;
-		
+
 		if (cg.weight > 0.000001)
 			cgx = cg.x;
 		else
 			cgx = Double.NaN;
-		
+
 		figure3d.setCG(cg);
 		figure3d.setCP(cp);
-		
+
 		// Length bound is assumed to be tight
 		double length = 0, diameter = 0;
 		Collection<Coordinate> bounds = configuration.getBounds();
@@ -625,7 +627,7 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 			}
 			length = maxX - minX;
 		}
-		
+
 		for (RocketComponent c : configuration) {
 			if (c instanceof SymmetricComponent) {
 				double d1 = ((SymmetricComponent) c).getForeRadius() * 2;
@@ -633,31 +635,31 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 				diameter = MathUtil.max(diameter, d1, d2);
 			}
 		}
-		
+
 		extraText.setCG(cgx);
 		extraText.setCP(cpx);
 		extraText.setLength(length);
 		extraText.setDiameter(diameter);
 		extraText.setMass(cg.weight);
 		extraText.setWarnings(warnings);
-		
+
 
 		if (figure.getType() == RocketFigure.TYPE_SIDE && length > 0) {
-			
+
 			// TODO: LOW: Y-coordinate and rotation
 			extraCP.setPosition(cpx * RocketFigure.EXTRA_SCALE, 0);
 			extraCG.setPosition(cgx * RocketFigure.EXTRA_SCALE, 0);
-			
+
 		} else {
-			
+
 			extraCP.setPosition(Double.NaN, Double.NaN);
 			extraCG.setPosition(Double.NaN, Double.NaN);
-			
+
 		}
-		
+
 
 		////////  Flight simulation in background
-		
+
 		// Check whether to compute or not
 		if (!((SwingPreferences) Application.getPreferences()).computeFlightInBackground()) {
 			extraText.setFlightData(null);
@@ -665,38 +667,38 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 			stopBackgroundSimulation();
 			return;
 		}
-		
+
 		// Check whether data is already up to date
 		if (flightDataFunctionalID == configuration.getRocket().getFunctionalModID() &&
 				flightDataMotorID == configuration.getMotorConfigurationID()) {
 			return;
 		}
-		
+
 		flightDataFunctionalID = configuration.getRocket().getFunctionalModID();
 		flightDataMotorID = configuration.getMotorConfigurationID();
-		
+
 		// Stop previous computation (if any)
 		stopBackgroundSimulation();
-		
+
 		// Check that configuration has motors
 		if (!configuration.hasMotors()) {
 			extraText.setFlightData(FlightData.NaN_DATA);
 			extraText.setCalculatingData(false);
 			return;
 		}
-		
+
 		// Start calculation process
 		extraText.setCalculatingData(true);
-		
+
 		Rocket duplicate = (Rocket) configuration.getRocket().copy();
 		Simulation simulation = ((SwingPreferences)Application.getPreferences()).getBackgroundSimulation(duplicate);
 		simulation.getOptions().setMotorConfigurationID(
 				configuration.getMotorConfigurationID());
-		
+
-		backgroundSimulationWorker = new BackgroundSimulationWorker(simulation);
+		backgroundSimulationWorker = new BackgroundSimulationWorker(document, simulation);
 		backgroundSimulationExecutor.execute(backgroundSimulationWorker);
 	}
-	
+
 	/**
 	 * Cancels the current background simulation worker, if any.
 	 */
@@ -706,22 +708,26 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 			backgroundSimulationWorker = null;
 		}
 	}
-	
+
-	
+
 	/**
 	 * A SimulationWorker that simulates the rocket flight in the background and
 	 * sets the results to the extra text when finished.  The worker can be cancelled
 	 * if necessary.
 	 */
 	private class BackgroundSimulationWorker extends SimulationWorker {
-		
+
-		public BackgroundSimulationWorker(Simulation sim) {
+		private final CustomExpressionSimulationListener exprListener;
+
+		public BackgroundSimulationWorker(OpenRocketDocument doc, Simulation sim) {
 			super(sim);
+			List<CustomExpression> exprs = doc.getCustomExpressions();
+			exprListener = new CustomExpressionSimulationListener(exprs);
 		}
-		
+
 		@Override
 		protected FlightData doInBackground() {
-			
+
 			// Pause a little while to allow faster UI reaction
 			try {
 				Thread.sleep(300);
@@ -729,36 +735,38 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 			}
 			if (isCancelled() || backgroundSimulationWorker != this)
 				return null;
-			
+
 			return super.doInBackground();
 		}
-		
+
 		@Override
 		protected void simulationDone() {
 			// Do nothing if cancelled
 			if (isCancelled() || backgroundSimulationWorker != this)
 				return;
-			
+
 			backgroundSimulationWorker = null;
 			extraText.setFlightData(simulation.getSimulatedData());
 			extraText.setCalculatingData(false);
 			figure.repaint();
 			figure3d.repaint();
 		}
-		
+
 		@Override
 		protected SimulationListener[] getExtraListeners() {
 			return new SimulationListener[] {
 					InterruptListener.INSTANCE,
-					ApogeeEndListener.INSTANCE };
+					ApogeeEndListener.INSTANCE,
+					exprListener};
+
 		}
-		
+
 		@Override
 		protected void simulationInterrupted(Throwable t) {
 			// Do nothing on cancel, set N/A data otherwise
 			if (isCancelled() || backgroundSimulationWorker != this) // Double-check
 				return;
-			
+
 			backgroundSimulationWorker = null;
 			extraText.setFlightData(FlightData.NaN_DATA);
 			extraText.setCalculatingData(false);
@@ -766,8 +774,8 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 			figure3d.repaint();
 		}
 	}
-	
+
-	
+
 
 	/**
 	 * Adds the extra data to the figure.  Currently this includes the CP and CG carets.
@@ -777,21 +785,21 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 		extraCP = new CPCaret(0, 0);
 		extraText = new RocketInfo(configuration);
 		updateExtras();
-		
+
 		figure.clearRelativeExtra();
 		figure.addRelativeExtra(extraCP);
 		figure.addRelativeExtra(extraCG);
 		figure.addAbsoluteExtra(extraText);
-		
+
-		
+
 		figure3d.clearRelativeExtra();
 		//figure3d.addRelativeExtra(extraCP);
 		//figure3d.addRelativeExtra(extraCG);
 		figure3d.addAbsoluteExtra(extraText);
-		
+
 	}
-	
+
-	
+
 	/**
 	 * Updates the selection in the FigureParameters and repaints the figure.  
 	 * Ignores the event itself.
@@ -803,16 +811,16 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 			figure.setSelection(null);
 			return;
 		}
-		
+
 		RocketComponent[] components = new RocketComponent[paths.length];
 		for (int i = 0; i < paths.length; i++)
 			components[i] = (RocketComponent) paths[i].getLastPathComponent();
 		figure.setSelection(components);
-		
+
 		figure3d.setSelection(components);
 	}
-	
+
-	
+
 
 	/**
 	 * An <code>Action</code> that shows whether the figure type is the type
@@ -823,13 +831,13 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 	private class FigureTypeAction extends AbstractAction implements StateChangeListener {
 		private static final long serialVersionUID = 1L;
 		private final int type;
-		
+
 		public FigureTypeAction(int type) {
 			this.type = type;
 			stateChanged(null);
 			figure.addChangeListener(this);
 		}
-		
+
 		@Override
 		public void actionPerformed(ActionEvent e) {
 			boolean state = (Boolean) getValue(Action.SELECTED_KEY);
@@ -841,11 +849,11 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 			}
 			stateChanged(null);
 		}
-		
+
 		@Override
 		public void stateChanged(EventObject e) {
 			putValue(Action.SELECTED_KEY, figure.getType() == type && !is3d);
 		}
 	}
-	
+
 }

core/src/net/sf/openrocket/gui/util/SwingPreferences.java

@@ -15,7 +15,6 @@ import java.util.prefs.BackingStoreException;
 import java.util.prefs.Preferences;
 
 import net.sf.openrocket.arch.SystemInfo;
-import net.sf.openrocket.document.OpenRocketDocument;
 import net.sf.openrocket.document.Simulation;
 import net.sf.openrocket.logging.LogHelper;
 import net.sf.openrocket.material.Material;
@@ -399,7 +398,7 @@ public class SwingPreferences extends net.sf.openrocket.startup.Preferences {
 	}
 	
 	public Simulation getBackgroundSimulation(Rocket rocket) {
-		Simulation s = new Simulation(new OpenRocketDocument(rocket), rocket);
+		Simulation s = new Simulation(rocket);
 		SimulationOptions cond = s.getOptions();
 		
 		cond.setTimeStep(RK4SimulationStepper.RECOMMENDED_TIME_STEP * 2);

core/src/net/sf/openrocket/optimization/services/DefaultSimulationModifierService.java

@@ -126,7 +126,7 @@ public class DefaultSimulationModifierService implements SimulationModifierServi
 		Rocket rocket = document.getRocket();
 		
 		// Simulation is used to calculate default min/max values
-		Simulation simulation = new Simulation(document, rocket);
+		Simulation simulation = new Simulation(rocket);
 		simulation.getConfiguration().setMotorConfigurationID(null);
 		
 		for (RocketComponent c : rocket) {

core/src/net/sf/openrocket/simulation/BasicEventSimulationEngine.java

@@ -90,12 +90,6 @@ public class BasicEventSimulationEngine implements SimulationEngine {
 				}
 				SimulationListenerHelper.firePostStep(status);
 				
-				// Calculate values for custom expressions
-				FlightDataBranch data = status.getFlightData();
-				ArrayList<CustomExpression> allExpressions = status.getSimulationConditions().getSimulation().getDocument().getCustomExpressions();
-				for (CustomExpression expression : allExpressions ) {
-					data.setValue(expression.getType(), expression.evaluateDouble(status));
-				}
 				
 				// Check for NaN values in the simulation status
 				checkNaN();

core/src/net/sf/openrocket/simulation/customexpression/CustomExpression.java

@@ -175,7 +175,7 @@ public class CustomExpression implements Cloneable{
 			names.add(type.getName());
 
 		if (doc != null){
-			ArrayList<CustomExpression> expressions = doc.getCustomExpressions();
+			List<CustomExpression> expressions = doc.getCustomExpressions();
 			for (CustomExpression exp : expressions ){
 				if (exp != this)
 					names.add(exp.getName());
@@ -412,7 +412,7 @@ public class CustomExpression implements Cloneable{
 	 */
 	public void addToDocument(){
 		// Abort if exact expression already in
-		ArrayList<CustomExpression> expressions = doc.getCustomExpressions();
+		List<CustomExpression> expressions = doc.getCustomExpressions();
 		if ( !expressions.isEmpty() ) {
 			// check if expression already exists
 			if ( expressions.contains(this) ){

core/src/net/sf/openrocket/simulation/customexpression/CustomExpressionSimulationListener.java

@@ -0,0 +1,34 @@
+package net.sf.openrocket.simulation.customexpression;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import net.sf.openrocket.simulation.FlightDataBranch;
+import net.sf.openrocket.simulation.SimulationStatus;
+import net.sf.openrocket.simulation.exception.SimulationException;
+import net.sf.openrocket.simulation.listeners.AbstractSimulationListener;
+
+public class CustomExpressionSimulationListener extends	AbstractSimulationListener {
+
+	private final List<CustomExpression> expressions;
+	
+	public CustomExpressionSimulationListener(List<CustomExpression> expressions) {
+		super();
+		this.expressions = expressions;
+	}
+
+	@Override
+	public void postStep(SimulationStatus status) throws SimulationException {
+		if ( expressions == null || expressions.size() == 0 ) {
+			return;
+		}
+		// Calculate values for custom expressions
+		FlightDataBranch data = status.getFlightData();
+		for (CustomExpression expression : expressions ) {
+			data.setValue(expression.getType(), expression.evaluateDouble(status));
+		}
+		
+
+	}
+
+}

core/test/net/sf/openrocket/optimization/rocketoptimization/TestRocketOptimizationFunction.java

@@ -1,7 +1,6 @@
 package net.sf.openrocket.optimization.rocketoptimization;
 
 import static org.junit.Assert.*;
-import net.sf.openrocket.document.OpenRocketDocument;
 import net.sf.openrocket.document.Simulation;
 import net.sf.openrocket.optimization.general.OptimizationException;
 import net.sf.openrocket.optimization.general.Point;
@@ -40,7 +39,7 @@ public class TestRocketOptimizationFunction {
 	@Test
 	public void testNormalEvaluation() throws InterruptedException, OptimizationException {
 		final Rocket rocket = new Rocket();
-		final Simulation simulation = new Simulation(new OpenRocketDocument(rocket), rocket);
+		final Simulation simulation = new Simulation(rocket);
 		
 		final double p1 = 0.4;
 		final double p2 = 0.7;
@@ -86,7 +85,7 @@ public class TestRocketOptimizationFunction {
 	@Test
 	public void testNaNValue() throws InterruptedException, OptimizationException {
 		final Rocket rocket = new Rocket();
-		final Simulation simulation = new Simulation(new OpenRocketDocument(rocket), rocket);
+		final Simulation simulation = new Simulation(rocket);
 		
 		final double p1 = 0.4;
 		final double p2 = 0.7;
@@ -123,7 +122,7 @@ public class TestRocketOptimizationFunction {
 	@Test
 	public void testOutsideDomain() throws InterruptedException, OptimizationException {
 		final Rocket rocket = new Rocket();
-		final Simulation simulation = new Simulation(new OpenRocketDocument(rocket), rocket);
+		final Simulation simulation = new Simulation(rocket);
 		
 		final double p1 = 0.4;
 		final double p2 = 0.7;
@@ -164,7 +163,7 @@ public class TestRocketOptimizationFunction {
 	@Test
 	public void testOutsideDomain2() throws InterruptedException, OptimizationException {
 		final Rocket rocket = new Rocket();
-		final Simulation simulation = new Simulation(new OpenRocketDocument(rocket), rocket);
+		final Simulation simulation = new Simulation(rocket);
 		
 		final double p1 = 0.4;
 		final double p2 = 0.7;
@@ -197,7 +196,7 @@ public class TestRocketOptimizationFunction {
 	public void testNewSimulationInstance() {
 		final Rocket rocket = new Rocket();
 		rocket.setName("Foobar");
-		final Simulation simulation = new Simulation(new OpenRocketDocument(rocket), rocket);
+		final Simulation simulation = new Simulation(rocket);
 		simulation.setName("MySim");
 		
 		RocketOptimizationFunction function = new RocketOptimizationFunction(simulation,

core/test/net/sf/openrocket/optimization/rocketoptimization/modifiers/TestGenericModifier.java

@@ -2,7 +2,6 @@ package net.sf.openrocket.optimization.rocketoptimization.modifiers;
 
 import static net.sf.openrocket.util.MathUtil.EPSILON;
 import static org.junit.Assert.assertEquals;
-import net.sf.openrocket.document.OpenRocketDocument;
 import net.sf.openrocket.document.Simulation;
 import net.sf.openrocket.optimization.general.OptimizationException;
 import net.sf.openrocket.rocketcomponent.Rocket;
@@ -21,9 +20,7 @@ public class TestGenericModifier {
 	@Before
 	public void setup() {
 		value = new TestValue();
-		Rocket rocket = new Rocket();
+		sim = new Simulation(new Rocket());
-		
-		sim = new Simulation(new OpenRocketDocument(rocket), rocket);
 		
 		Object related = new Object();